The present invention relates to an electronic wallet, equipment associated therewith, and a method of using an electronic wallet.
The use of smart cards as electronic wallets is well known. A smart card can store electronic credits, representing money, which can be transferred by electronic means from a payer, the owner of the smart card, to a payee, the person with whom a cash transaction is conducted. However, in order to conduct a transaction with an electronic wallet, it is necessary to hand the wallet over to the payee, who will then insert the wallet (smart card) into a till having a smart card reader, enter the sum to be paid into the till which will then deduct the sum from the credits held on the smart card. In cash terms, this amounts to paying for a meal in a restaurant by handing a wallet, containing cash in the form of bank notes to a waiter, allowing him to take the wallet away and remove the cash from it necessary to pay the bill. From the point of view of the payer, this is not entirely a satisfactory way of conducting a cash transaction and entails placing a great deal of trust in the payee.
The use of mobile telephones is now well established. Many mobile telephone systems use SIMs, subscriber information modules, which are in the form of smart cards. A SIM carries a variety of information about a mobile telephone subscriber and the service he is entitled to access. SIMs are usually protected by a PIN (personal identity number), and include encryption algorithms and keys. To use a particular mobile telephone, a subscriber inserts his SIM into the telephone and enters his PIN, service is then available to him from the mobile telephone into which the SIM has been inserted. A similar system can be used to give a subscriber access to a payphone. Transmission over modern digital mobile telephone systems, such as the GSM system, is encrypted. The encryption employed frequently involves the use of asymmetric cyphers, which enable both secure encryption and the use of secure electronic signatures.